1. Field of the Invention
The present invention relates to expansion joints and expansion joint covers. More particularly, the present invention relates to an expansion joint cover that can accommodate variations in separation distance, vertical offset, lateral offset, and torsion between two surfaces of an expansion joint.
2. Description of Prior Art
Buildings are typically constructed of rigid materials such as concrete and steel which are chosen for their ability to support loads and resist movement under those loads. Unfortunately, such rigid materials sometimes experience failures when they expand or contract due to changing temperatures or when they move due to seismic events.
To prevent failures, it is common practice to build expansion joints into buildings. Expansion joints are essentially gaps between two rigid surfaces of a building which allow the two surfaces to move with respect to each other without the failures described above.
Typically, an expansion joint is either filled, covered, or both. An expansion joint can be filled with a flexible material with desired characteristics such that it is, for example, waterproof and/or fire resistant. While the flexible material may effectively seal the expansion joint, it is typically not aesthetically appealing and therefore is often covered.
There are several expansion joint cover designs in the prior art. Some cover designs incorporate a plate which is secured to one of two surfaces to span an expansion joint between the two surfaces. An end of the plate typically slides against the other surface in order to accommodate variations in separation distance and vertical offset. These designs cannot effectively accommodate variations in lateral offset and torsion between the two surfaces.
Another design includes a plate that slides within at least one housing. The housing is secured to one of two surfaces of an expansion joint. The plate is secured to the other surface. The plate slides within the housing in order to accommodate variations in separation distance. However, the internal dimensions of the housing limit the allowable lateral offset and torsion between the two surfaces.
An improved design includes a plate with a first end connected to one of two surfaces of an expansion joint by a hinge. A second end of the plate slides within a housing, which is fixedly mounted to the other surface. The plate is thus able to accommodate variations in separation distance between the two surfaces. The hinge is able to accommodate variations in torsion between the two surfaces. However, the internal dimensions of the housing still limit allowable lateral offset between the two surfaces.
Accordingly, there is a need for an expansion joint cover that overcomes the limitations of the prior art. Specifically, there is a need for an expansion joint cover that can accommodate variations in separation distance, vertical offset, lateral offset, and torsion between two surfaces of an expansion joint.
The expansion joint cover of the present invention overcomes the above-identified problems and provides a distinct advance in the art of expansion joints. More particularly the present invention provides an expansion joint cover that can accommodate variations in separation distance, vertical offset, lateral offset, and torsion between two surfaces of an expansion joint.
The expansion joint cover is preferably used to cover an expansion joint comprising a first surface and a second surface. The preferred embodiment of the expansion joint cover broadly comprises a first plate, a second plate, a first hinge assembly hingedly attaching the first plate to the first surface, a second hinge assembly hingedly attaching the first plate to the second plate, and a housing fixedly secured to the second surface. The first plate includes an exterior surface, where a facade can be secured, in order to enhance aesthetic appeal of the expansion joint cover.
The second plate similarly includes an exterior surface, where a facade can be secured. The second plate also includes a positioner secured to an internal end. The positioner includes two low-friction seals that allow the internal end to slide within the housing.
The first hinge assembly and the second hinge assembly are similar and both include a hinge and a face seal. The face seal is flexible and covers the hinge in an aesthetically appealing manner.
The housing includes a front plate, a rear plate, a tension block, a hinge, and a face seal. During installation, the front plate can rotate about the hinge to allow the second plate to be installed within the housing. The front plate includes a front standoff and a low friction seal that seals the front plate to the facade of the second plate. The rear plate similarly includes a rear standoff and a low friction seal that seals the rear plate to the second plate. The face seal is flexible and covers the hinge in an aesthetically appealing manner.
An installer installs the expansion joint cover by first mounting the first hinge assembly to the first surface and the rear plate to the second surface. Then, the installer mounts the facade to the first and second plates and places the second plate within the housing. Then, the installer secures the front plate against the second plate by driving a tension bolt through the front plate and into the tension block. Finally, the installer mounts the facade to the front plate.
Alternatively, the housing may include only a front plate, a rear plate, and a bracket. The front plate and the rear plate would include the standoffs and low friction seals discussed above. The bracket may be a separate component that is attached, affixed, or integral to the rear plate. The front plate is secured to the bracket using mechanical fasteners, adhesives, tapes, and/or welds. This would negate the need for the tension block, the hinge, and the face seal.
In use, the second plate slides within the housing to accommodate variations in separation distance and vertical offset between the two surfaces. The two hinge assemblies accommodate variations in torsion between the two surfaces. The combination of the second plate sliding within the housing and the two hinge assemblies accommodates variations in lateral offset between the two surfaces.